WHY AGRONOMISTS SHOULD BE CONCERNED ABOUT INVASIVE PLANTS

Mark J. RenzAssociate Professor

Extension Weed Specialist

Outline

• What is an invasive plant and how are they regulated in WI?

• What are the potential impacts to agriculture?

• Things you can do to help

What is an invasive species?

• NR 40, WI-DNR (2009): A nonnative species including hybrids, cultivars, subspecific taxa, and genetically modified variants whose introduction causes or is likely to cause economic or environmental harm or harm to human health”

• 75 plants are regulated– 27 prohibited, 36 restricted, 12 split

http://docs.legis.wisconsin.gov/code/admin_code/nr/001/40.pdf

DNR assessed positive/negative attributes of non-native species

• This is what was done in making NR-40 rule– Look under literature

summary in DNR website• Research/summarized

known information• Involved stakeholders in

the process

– Results were from a statewide perspective

Difference between prohibited and restricted species

Example of ProhibitedKudzu Wild Parsnip

Example of Restricted

Many regulated terrestrial plants are/can impact agriculture

# Present in WI

Invades ag lands

Examples

Prohibited 18 50 % 28% yellow star thistle

Split listed 12 100% 67% poison hemlock

Restricted 32 100% 63% Canada thistle

TOTAL 62 85% 52%

Economic Impacts From Invasive Plants

• Livestock performance reduced/death– Poison hemlock – Yellow star thistle

• Yield reduced– Canada thistle– Buckthorn/honeysuckle

• Costs to manage crop increase– Direct: Canada thistle – Indirect: Soybean aphid that overwinters on

buckthorn

Environmental and human health Impacts From Invasive Plants

Environmental– Soil erosion increased due to displacement of

grasses from spotted knapweed

Human health– Japanese barberry increases ticks /lyme disease– Wild Parsnip: Phyto-photo-sensitivity– Bush honeysuckle increase lone-star tick and

associated diseases

How to prevent/minimize impact?

1. Prevent invasions from establishing– National and statewide efforts

2. Detect invasions early and eradicate (EDRR)– Local efforts work best• Most effective and efficient method of control• Cooperative efforts already in place at local level– Allow for sharing of resources (CISMA=CWMA)

An example of why early detection is important!

Amur honeysuckle invasion • After 10 years of invasion,

reductions in in forest herb regeneration can be observed

• After 20 years of invasion many native plants seeds are not present in the soil– irreversible change

Image courtesy of missouriplants.com

Case Study #1 Poison Hemlock

• Invades roadside ditches, pastures, and waterways

• White flowers up to 10’ tall

• Stem have reddish-purple splotches

• Spreading via roads in southern WI

• Less than a pound ingested is toxic

Case Study #2 Spotted knapweed

• grows 2–4’ tall • showy pink to purple

flower from one or multiple stems.

• Displaces desirable grasses and forbs.

• fields infested have – > 2X the water runoff– 4X more sediment

removal

Case Study #3 Common Buckthorn

• Understory shrub or small tree 10–25’ tall. – yellow/orange colored wood if

cut– earliest shrub to leaf-out in the

spring and last to lose its leaves in the fall.

• Primary overwintering location for the soybean aphid. – $$$ to control infestations and

prevent yield loss

Relationship between buckthorn infestation and acres sprayed?

Heimpel et al. 2010

Case Study #4 Kudzu Bug

• Non-native insect to US– Not present in WI– Discovered in US in 2009– Rapidly spreading north– Uses Kudzu as a primary

overwintering site

• Feeds on soybeans– In SE US, average yield loss

from untreated fields 20%– Can be managed with

insecticides ($)

Potential Kudzu Bug Impact• Impact in south is 10-30% yield loss• Wisconsin has 1.5 million acres of

soybeans– 2013 60 million bushels = $ 725,000,000

• If 10% yield reduction in Wisconsin– $72.5 Million Dollar loss

• If treated ½ fields ($20/A) – $15 Million Dollar cost

Case Study #5 Japanese Barberry

• Common ornamental shrub – typically 2-3’ tall– Branches are reddish-brown

and deeply grooved, with a single sharp spine at each node

• It invades forests, changing factors related to forest regeneration and health

• Provides ideal habitat for deer ticks– involved in the continued

spread of Lyme disease

Forest in the Wisconsin Dells

Summary

• Many other examples than these–Many serve as alternate hosts for diseases• Vegetable industry

• Often the impact is unknown at the time of introduction

• If these new plants have no value is it worth the risk to allow them to persist?

Resources to Assist in ID and Control

• http://fyi.uwex.edu/weedsci/ –36 factsheets ID and control

–18 YouTube videos on ID (regulated species)

–http://weedid/wisc.edu = >300 species ID

–http://mipncontroldatabase.wisc.edu

How can you help?

Goal is to prevent spread of plants

• Most effective way is to detect plants early and eradicate before they become widespread–Knowledge of new infestations is most often

the limiting factor– Limited funding may be available to assist

with management for PROHIBITED SPECIES

Report new infestations

Several options on how to report1. Contact me, DNR staff, county agent2. Submit observation via the Great Lakes Early

Detection Network1. Online through website www.gledn.org2. Mobile App• To download go to

http://apps.bugwood.org/mobile/gledn.html

Simple Report Form

• Functional on apple/android• Smartphones• tablets

• Report across taxa• Terrestrial and Aquatic Plants• Insects• Plant Pathogens• Aquatic Invertebrates• Fish• Animals• Fish and Animal Diseases

http://apps.bugwood.org/mobile/gledn.html

Details of App

• Add a picture

• GPS location

• Time spent monitoring

• Infestation information/notes

Can make an observation < 1 min

For a video tutorial see or contact me for the link

• https://www.youtube.com/watch?v=ZzTjEM0F6C0&index=2&list=PLLq7T9GBdf8wbGakjYDc7tYgrJ8x8HKgi

• 5 minutes long– Intro to • Downloading the App• How to register• How to submit an observation• How to draw a polygon

What happens when a report is submitted?

• Verified– Picture, visit

• Shared with the public– Alert will be sent out to concerned land managers

• Available for research and outreach– Updating regulations towards species– Predicting future spread of species– Motivate local groups to take action to control

new populations

Summary

• Invasive plants can impact agriculture!

• The most effective way to manage invasive plants is through – Prevention– Early detection and eradication

• Reporting new infestations can help prevent many of these impacts– Resources to assist in reporting

Thank you!Questions?

mrenz@wisc.edu

NR 40 is being revised

• Proposed revisions:–Delisting 2 species (0 plants)–Changing the regulated status of 6

species (2 plants)–Listing 83 new species• 49 prohibited (41 plants, 19 aquatic)• 32 restricted (29 plants, 3 aquatic)• 2 plants split-listed